The "scaled" size is what the forum software has done to it AFTER it was downloaded at full res from Photobucket.

Doesn't Photobucket offer an option to link the same pic in different resolutions (and therefore file sizes)?
Or resize the res/ file size at time of upload?
SmugMug offers 4 or 5 different resolutions, with a separate link each.
Don't know about Flickr....Imgur offers 3 sizes, Google knocks them down to 1080 width on upload unless you want to use their "big-file" quota.

My picxs out of the Panasonics are all around the 5-8mb off the SD-card....I then quickly batch-resize them with one of the many free resize tools
(i.e. 600 pics take about 30 seconds processing)https://duckduckgo.com/?q=jpg+batch+...=v110-1&ia=web
before uploading to the photo-site.
IrfanView is a free piece of software that does batch rename+resize all in one hit...as well as handle nearly any grafix format on the planet.

This way I get fast uploads.... as well as quick-opening pages with lots of photos.